When does a package need to use ::: for its own objects

问题

Consider this R package with two functions, one exported and the other internal

hello.R

#' @export
hello <- function() {
  internalFunctions:::hello_internal()
}

hello_internal.R

hello_internal <- function(x){
    print("hello world")
}

NAMESPACE

# Generated by roxygen2 (4.1.1): do not edit by hand

export(hello)

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When this is checked (devtools::check()) it returns the NOTE

There are ::: calls to the package's namespace in its code. A package
  almost never needs to use ::: for its own objects:
  ‘hello_internal’

---

Question

Given the NOTE says almost never, under what circumstances will a package need to use ::: for its own objects?

---

Extra

I have a very similar related question where I do require the ::: for an internal function, but I don't know why it's required. Hopefully having an answer to this one will solve that one. I have a suspicion that unlocking the environment is doing something I'm not expecting, and thus having to use ::: on an internal function.

If they are considered duplicates of each other I'll delete the other one.

回答1:

You should never need this in ordinary circumstances. You may need it if you are calling the parent function in an unusual way (for example, you've manually changed its environment, or you're calling it from another process where the package isn't attached).

来源：https://stackoverflow.com/questions/36852140/when-does-a-package-need-to-use-for-its-own-objects